Television Tape Recording Research Articles

Proposed SMPTE Recommended Practice: Audio Levels for Digital Audio Records on Digital Television Tape Recorders

Proposed SMPTE Recommended Practice: Audio Levels for Digital Audio Records on Digital Television Tape Recorders

The Interfacing of AES/EBU Serial Digital Audio Signals with D-1, D-2, and D-3 Format Digital Television Tape Recorders

This tutorial was written at the request of the Working Group on DTTR Format Applications, which is one of the subgroups of the SMPTE Committee on Television Recording and Reproduction Technology. It is intended to acquaint the reader with how the auxiliary data of the AES/EBU signal is utilized in the various implementations of the existing D-1, D-2, and D-3 digital television tape recorder (DTTR) formats and some of the problems likely to be encountered in the use of AES/EBU serial digital audio signals with DTTRs.

Electrical System Design for the SMPTE D-1 DTTR

The design of the electrical system for the D-1 digital television tape recorder (DTTR) was developed after that of the mechanical system. This article describes the process of finding the best solution for synchronization, error protection, and video/audio sample distribution. Following an explanation of video segments and video sectors, the distribution of the four audio signals is discussed. The tracking control record is also explained.

The SMPTE Type D-1 Digital Television Tape Recorder — Error Control

This article will explain the method of error control employed in the SMPTE D-1 digital television tape recorder (DTTR). It starts with an outline of the fundamental aspects of information engineering, and follows with a description of the error-control scheme objectives. The nature of redundancy against error-correcting power is explained, together with the constraints set by the operational requirements of slow-motion and high-speed shuttle replay. The use of a combined error-correcting, error-detecting code is described, and aspects of the error-control performance are calculated in detail.

Measurement Methods and Diagnostic Techniques for the Digital Television Tape Recorder (DTTR)

Measurement Methods and Diagnostic Techniques for the Digital Television Tape Recorder (DTTR)

The Digital Television Tape Recorder — Audio and Data Recording Aspects

The digital television tape recorder (DTTR) is expected to achieve very high video performance. Audio performance must be comparable while offering far greater operational facilities and flexibility. The designer of the audio systems for the DTTR is constrained in many directions — user needs, specified performance, relationships to the video channel, and interconnection to a completely digital production facility — while having to be conservative in terms of circuit complexity and reliability. There are few precedents to rely on, and the specification of the audio and data formats has produced novel ideas and concepts heretofore unknown in television technology. This article outlines requirements and constraints, proposes a format that meets them, and offers several new features not currently found in analog recording.

The Effect of Word Distribution on the Error Management of Digital Television Recorders

In the SMPTE and the European Broadcasting Union, groups are working toward a single format for digital television tape recording. This paper discusses the relative benefits of different methods of distributing words, both on the tape and between one head and another. The use of every head on all parts of the picture is shown to be beneficial. This conclusion is reached both from considerations of head clogging and of variations of performance between one head channel and another. Formats with one group of clustered heads are the only formats which automatically result in all heads being used equally on all parts of the picture, ensuring freedom from head-banding.

Standardization in Quadruplex Television Tape Recording

Basic standards are derived by pioneers in the field and the resulting documents become part of the foundation of the industry. As the industry matures, however, there is a tendency for the original reasoning behind these standards to be lost or dimmed with time, resulting in loss of respect for certain standards. In the videotape-recording industry, this is most notable in penetration, because of the ease with which the standard may be violated, the lack of immediate dire consequences from its violation, and the superficial advantages which accrue from under-penetration. The technical basis for the SMPTE Recommended Practice which specifies vacuum guide radius and position (hence, penetration), is described and the critical need for adhering strictly to this specification is emphasized. The reasoning behind other standards of the VTR industry, and how the industry benefits from careful respect for these standards, is reviewed.

Frame Numbering of Television Tape Recording

A phase-modulated data signal for recording TV frame numbers on the cue audio track is described. Each frame period includes a series of binary-coded decimal (BCD) numbers arranged in hours, minutes, seconds and frames, and an additional data period for logging information. Also included is a synchronizing interval which marks the end of each frame, and from which tape speed and direction are sensed. Preamplifier requirements for playback over a wide speed range are discussed.

The use of the protable television tape recorder in science education

The use of the protable television tape recorder in science education

Miami–Dade's Encounter with Technology

1 V liami-Dade Junior College the master control room: electronic circuits, monitors, television tape recorders, walla. Four programs, running at once, are being piped to classrooms by closed circuit cables: The Central Nervous System, The Concept of Culture, So That Men Are Free, The Thread of Life. The programs are in living color slide-tapes, films, CBS Reports, the music of Simon and Garfunkel. This, says a technician, a problem of packaging. don't have other stations to compete with, the kid can't flip channels, but we hope to keep him from going to sleep. The talk is about efficiency, inputs, programming, dubs, systems. Miami-Dade, one of those instant colleges, has grown from zero to 25,000 students on two campuses in eight years. Super-pragmatic and super-audacious, it is running ahead of its own institutional identity crisis, testing itself not by grace or elegance, but by numbers and dropouts, by senior college admissions, and by the economic usefulness of its graduates. We're only number two a junior college, says Franklin Bouwsma, the chief guru of hardware. We have to try harder.

TELEVISION TAPE RECORDING AND CINEFLUOROGRAPHY IN ROUTINE FLUOROSCOPIC PROCEDURES: A COMPARATIVE STUDY.

Television tape recording of fluoroscopic images is by no means new (5, 6). Until relatively recently, owever, such recording required large expensive television tape recorders under constant skilled pervision by technical and engineering personnel. This placed their use out of the reach of all but very large specialized institutions. With the advent of transistorized, compact helical scan recorders, the size and price limitations have been largely overcome. Such devices are now within the reach of the clinical radiologist in the community hospital or private office practice. Since August, 1963, it has been our custom to employ a video tape-recording device routinely in our luoroscopic procedures. During this period, many radiologists have shown considerable interest in this modality. This interest has prompted a review of the subject and a comparison of its merits with those of the other means of physiologic recording, cineradiography. I t is neither possible nor desirable to attempt to give an elaborate...

F.M. systems of exceptional bandwidth

Until the advent of television tape recorders, the only frequency-modulated systems in use were ones in which the frequency spectra of the modulating and modulated signals were well separated. In television tape recorders these bands are not merely adjacent but actually overlap. The analysis of such systems of ‘exceptional bandwidth’ emphasises three points:(a) The instantaneous frequency and amplitude of a waveform cannot be uniquely defined; the approximations involved become serious in such systems.(b) It follows that one cannot synthetise a distortionless f.m. system. It is therefore important to distinguish the implicit distortion from that which may be avoided.(c) These systems are very sensitive to amplitude distortion and, especially, to second-order components.Finally, the paper discusses the practical design of modulators and demodulators.

Televex-tape-kinescopy and cineradiography. Comparison of two methods of recording fluoroscopy.

At the 1960 meeting of the Radiological Society of North America in Cincinnati, the authors reported their preliminary experience with closed-circuit television viewing and with closed-circuit television tape recording of the fluoroscopic image (1). The fluoroscopes in the fluoroscopic rooms of the x-ray department and the cardiac catheterization laboratory at the Children's Hospital of Pittsburgh are equipped with Televex (by Westinghouse) image Orthicon television cameras optically coupled to Philips 9-inch image amplifiers. The fluoroscopic examinations are recorded simultaneously on television tape, exactly as they are viewed on the closed-circuit monitors, without loss of picture quality or detail and at the same low levels of radiation required for closed-circuit television viewing alone. Television tape is now a proved method of routine recording of the fluoroscopic image. The combination of television tape (RCA) recorder and Televex (Westinghouse) has been in regular use at the Children's Hospital of Pittsburgh since November 1960. All fluoroscopic examinations from the three regular fluoroscopic rooms are recorded in their entirety on television tape. The taped examinations are reviewed by the professional staff of the radiology department and are transferred to 16-mm. movie film via the kinescopic recorder. The 16-mm. film is processed in the automatic developer (X-omat) and is available for projection on a 16-mm. projector at regular, slow motion or single frame speeds. The transfer to movie film is made without obvious loss of picture quality or detail. A standard 16-mm. cinefluorographic camera views the output phosphor of the image amplifier in the cardiac laboratory. Selective angiography is simultaneously recorded directly on 16-mm. film and on television tape. The taped recording is immediately played back to a monitor in the laboratory, where the cardiologist reviews the examination as often as is necessary for him to determine whether it is technically satisfactory and contains the desired information. The cine film is then processed; if it proves technically satisfactory, the taped examination is erased If the cine examination is not satisfactory, the taped examination is transferred to film via the kinescopic recorder. Comparison of Tape vs. Cine For purposes of discussion, arbitrary definitions are needed. “Cine” and “cine-fluorography” refer to motion picture recording of the image on the output phosphor of an image amplifier. “Television tape recording” indicates magnetic tape recording of the information on the output phosphor of an image amplifier mediated through a television camera. The cameras referred to in this article are specially designed, “image Orthicon” in type.

The Technology of Television Program Production and Recording

The basic concepts for television origination equipment are determined by operational requirements, which have remained relatively constant throughout the history of television broadcasting. In brief, television cameras and related studio equipment are designed to permit the assembly of a smooth flow of picture and audio signals from multiple sources, including both live scenes and prerecorded material. The photography of kinescope images on motion-picture film was an early approach to practical television recording which still offers enough advantages that major engineering efforts continue to be placed on the development of improved film recording equipment. A great deal of the current television recording activity, however, involves the use of magnetic tape. The most common types of television tape recorders employ 2-in. wide magnetic tape, on which picture information is recorded by rotating video heads which produce tracks extending across the width of the tape. Four separate heads are mounted on the rotating headwheel, but switching circuits are employed to deliver a single continuous signal during the playback process. Through the use of FM techniques and precise servomechanisms, it is possible to accomplish television tape recording with extremely high picture quality.

Large screen image amplification with closed-circuit television employing television tape-recorder.

The ever increasing public emphasis on the hazards of radiation and the ever expanding fields of motion radiography present challenges to the radiologist and to the manufacturer of x-ray equipment. At the same time that more extensive use of motion studies is made, every effort must be concentrated on limiting the amount of radiation during any given examination. The recently opened x-ray department at the Children's Hospital of Pittsburgh utilizes television tape-recording of the fluoroscopic image, mediated through a newly developed image Orthicon television camera2 optically coupled to a 9-inch image amplifier. The system permits recording on television tape and simultaneous viewing on the closed-circuit television monitor at the same low levels of radiation as are required for closed-circuit television viewing alone. This paper will outline some of the considerations that went into the planning of the department. Image amplifiers with field diameters of 4 1/2 and 5 inches have been available for nine years. They have the disadvantages of limited field size and inconvenience of viewing by more than one observer. The optical coupling of Vidicon television cameras with these amplifiers to record the fluoroscopic image on closed-circuit television monitors solved the problem of viewing but necessitated increased amounts of radiation for adequate visualization of the field under observation. Satisfactory cineradiographic film recording of the fluoroscopic image on the amplifier requires a major increase in radiation. In the course of investigation of available systems of image amplification, particularly with reference to larger field size, the authors became interested in the General Electric TVX system, which employed closed-circuit television as an integral part of its operation. It offered the potential advantage of television viewing at diminished rates of radiation but raised the problem of recording the television image. Kinescopic movie-film recording of the image on the television screen is relatively difficult technically, moderately expensive, and attended by film problems inherent in other cineradiographic methods. Television tape-recording affords the ideal method for reproduction of the picture on the television monitor. The identity of an original picture with its television-taped reproduction is apparent to any home television viewer. Television tape also offers the advantages of immediate playback for review, and of availability to all fluoroscopic rooms. An additional cable run from the television camera to the tape-recorder allows recording from each fluoroscopic unit. Television tape-recording is possible at the level of radiation required for closed-circuit television monitor viewing.

Operational facilities in the RCA colour television tape recorder

The design of the recorder makes many new operating facilities available as integrated parts of the recorder. The electrical delay adjustments are intended to make greater precision readily available and facilitate tape interchangeability. A detailed account is given of the manner of making the adjustments to reduce quadrature errors at the heads.

A mobile television camera and recording vehicle

The paper describes the design and construction of a mobile television camera and recording unit which mounts all the necessary apparatus to televise and record live scenes, even while the vehicle is in motion. The mobile unit contains a television tape recorder, two image orthicon cameras, vision and sound mixing equipment, a synchronizing-pulse generator and a petrol-electric alternator set, as well as miscellaneous accessory equipment. Details are given of vision and sound facilities and power supply system; the mechanical arrangement of the vehicle and equipment mounting is also described.